iRedMail doesn't ship PostfixAdmin since iRedMail-0.7.0, but the core columns in iRedMail SQL structure are almost same as PostfixAdmin, so you can install PostfixAdmin manually for MySQL backend to manage mail accounts.

query = SELECT mailbox.transport FROM mailbox,domain WHERE mailbox.username='%s' AND mailbox.domain='%d' AND mailbox.domain=domain.domain AND mailbox.transport<>'' AND mailbox.active=1 AND mailbox.enabledeliver=1 AND domain.backupmx=0 AND domain.active=1